Are balance and lower extremity muscle strength correlated with fracture risk independent of bone mineral density in postmenopausal women?: A cross-sectional study.

Abstract

Background: Postmenopausal women are at increased risk of fractures due to reduced bone mineral density (BMD) and impaired physical function. While fracture risk assessment tools like FRAX include clinical factors and BMD, they exclude functional measures such as balance and muscle strength, which are critical for fall prevention. This study aimed to evaluate the correlation between two functional tests- the 30-Second Sit to Stand Test (30STS) and the One Leg Stance Test (OLST)- and fracture risk, independent of BMD in postmenopausal women aged 50-70.

Methods: This cross-sectional study included 156 postmenopausal women aged 50-70. Fracture risk was assessed using FRAX. Postural balance was evaluated using the OLST, while lower extremity muscle strength was measured with the 30STS. Both tests were analyzed for correlations with 10-year risks of major osteoporotic fractures (MOF), hip fractures, femoral neck BMD, and T-score at the lumbar spine and femoral neck. Participants were grouped based on OLST (<10 s) and 30STS (<15 repetitions) cut-offs, and fracture risks were compared.

Results: OLST and 30STS scores were significantly negatively correlated with 10-year hip fracture risk (r = -0.347, p < 0.001 and r = -0.197, p = 0.014, respectively). A significant negative correlation was also observed between OLST scores and 10-year MOF risk (r = -0.245, p = 0.002). Participants with OLST <10 s had significantly higher 10-year hip and MOF risks, while those with 30STS <15 had significantly higher 10-year hip fracture risk only. No correlation was found with femoral neck BMD.

Conclusion: LST and 30STS are associated with fracture risk independent of BMD in postmenopausal women aged 50-70. These practical tests may help identify individuals at higher fracture risk and support early interventions.